Research on a prediction method of wind environment for a region consisting coastal area and off-shore structures

本研究的目的是发展一种数值和实验方法来预测复杂地形中由近海和近海组成的区域的风环境。在数值方法方面，我们重点发展了计算地形的网格生成方法，计算高雷诺数流动的方法，如LES，以及入口和地面的边界条件的技术。作为结果，我们成功地开发了一种网格生成方法，使用矩形网格近似技术，使我们能够轻松有效地生成计算网格。这种方法在新的功能中将非常有用，因为计算机能力将逐年发展。采用大涡模拟方法模拟高雷诺数流动。在各种湍流模型中，大涡模拟是最有希望的湍流模拟方法。对于边界条件，为了在计算机域的入口处给出合适的湍流条件，我们采用了一种预域方法来计算湍流入流。在风洞实验中，对复杂地形上的流动进行了平均速度测量和流动显示实验，并与数值分析结果进行了比较。综上所述，尽管近海地区的风环境预测在数值方法和实验方法上还存在一些问题，但已经成功地建立了一个由数值分析和风洞实验组成的系统。

The objectives of the present research are to develop a numerical and experimental method to predict the wind environment for a region consisting of off shore and near sea in a complicated terrain. For the numerical method, we have focused on the development of grid generation method for computing terrain a method for computing high Reynolds number flows, such as LES, and a technique for boundary conditions for the inlet and ground. As the results, we have successfully developed a method for grid generation, by using a rectangular grid approximation technique, which enable us to generate a computational grid easily and effectively. This method will be very useful in a new feature, because the computer ability will develop year by year. A LES method has been employed to simulate high Reynolds number flows. Among turbulence models, LES is a most hopeful method for the simulation turbulence field. For the boundary conditions, to give a suitable turbulent conditions at the entrance of the computer domain, we have adopted a pre-domain method to compute the turbulent inflows. For the wind tunnel experiment, mean-velocity measurement and flow visualization experiment of the flow over a complex terrain was carried out to compare the results with those in numerical analyses. Both results show almost good agreement except for the region near ground.To sum up, although there still remain a couple of problems both in numerical and experimental method for the prediction of wind environment near coastal area, a system consisting of the numerical analysis and wind tunnel experiment has been successfully developed.